Modern motor vehicles, such as automobiles, generally include electrical systems that include one or more storage batteries (e.g., rechargeable lead acid storage batteries) and alternators that cooperatively provide the electrical power for many vehicle functions. For example, the automobile battery provides electrical power to start the vehicle engine and also provides the electrical power to operate various vehicle accessories when the alternator is providing insufficient power to meet the electrical demands of the vehicle. Presently, vehicles are being designed that include more accessories than in the past (e.g., heated cup holders and temperature controlled seats) to meet the desires of drivers and passengers. Accordingly, such vehicles have a greater dependence on the batteries. As automotive vehicles continue to evolve, forecasts predict that even more electrically enabled functions will be provided to accommodate increasing driver and passenger desires, which further increases the future importance of the batteries.
It is well known that the exposure of batteries to either adversely hot or cold temperatures for prolonged periods has a deleterious effect on operating output performances, recharging abilities and operating lifetime. Automotive batteries are typically located in or near internal combustion engines that produce high temperatures, which tend to undesirably heat the batteries. High ambient temperatures external to the automobile can further elevate the temperatures of the batteries and conversely, low ambient temperatures external to the automobile can undesirably decrease battery temperatures.
For example, the desired temperature for operation of a lead acid battery is approximately twenty-five degrees centigrade (25° C.) and temperatures less than this temperature can diminished electrochemical activity, which results in the battery having an output voltage with a lower magnitude and less than maximum discharge current. Moreover, the useful life of a lead acid battery is cut in half for approximately every increase of ten degrees centigrade (10° C.) in battery temperature that is greater than about twenty-five degrees centigrade 25 (10° C.).
Prior to the present invention, insulating cases have been provided for at least partially isolating automotive batteries from the heat created by the vehicle engine and from the ambient temperature extremes. However, the insulating cases can undesirably subject batteries to trapped heat, for example. Other more sophisticated prior art battery temperature control systems have employed expensive compressors designed to circulate a refrigerant through a cold plate for cooling a battery and/or heat sinks for dissipating heat from the battery. Moreover, electric heaters employing resistive elements heated by electricity have been used to warm batteries subjected to adversely cold temperatures.
In view of the foregoing, it should be appreciated that there is a need to provide improved apparatuses for controlling the temperature of a battery in order to maintain the temperature of the battery within a predetermined temperature range. In addition, there is a need to provide improved methods for controlling the temperature of a battery in order to maintain the temperature of the battery within a predetermined temperature range. It is desirable that such temperature control methods and apparatus are relatively inexpensive, simple, efficient, reliable and expeditious. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent brief summary, detailed description, appended claims, and abstract, taken in conjunction with the accompanying drawings and the foregoing technical field and background.